Introduces ability for session to wait on a migration trigger for a new

net/quic/chromium/quic_chromium_client_session.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // A client specific QuicSession subclass.  This class owns the underlying
 // QuicConnection and QuicConnectionHelper objects.  The connection stores
 // a non-owning pointer to the helper so this session needs to ensure that
 // the helper outlives the connection.
 
 #ifndef NET_QUIC_QUIC_CHROMIUM_CLIENT_SESSION_H_
@@ skipping 255 matching lines @@
   // to be the new default writer. Returns true if socket was
   // successfully added to the session and the session was
   // successfully migrated to using the new socket. Returns true on
   // successful migration, or false if number of migrations exceeds
   // kMaxReadersPerQuicSession. Takes ownership of |socket|, |reader|,
   // and |writer|.
   bool MigrateToSocket(std::unique_ptr<DatagramClientSocket> socket,
                        std::unique_ptr<QuicChromiumPacketReader> reader,
                        std::unique_ptr<QuicChromiumPacketWriter> writer);
 
+  // Method to call when NetworkChangeNotifier notifies observers of a
+  // new network. Tries to migrate any sessions that are waiting for a
+  // new network to connect.

[Ryan Hamilton, 2016/09/13 00:33:18]

nit: This comment talks about "any sessions" but presumably it only applies to
this session?

[Jana, 2016/09/13 01:12:19]

Fixed comment.

+  void OnNetworkConnected(NetworkChangeNotifier::NetworkHandle network,
+                          const BoundNetLog& bound_net_log);
+
+  // Schedules a migration alarm if one isn't already pending to wait
+  // for a new network.
+  void OnNoNewNetwork();
+
+  // If migration alarm was not cancelled, closes session with error.
+  void OnMigrationTimeout();
+
   // Populates network error details for this session.
   void PopulateNetErrorDetails(NetErrorDetails* details);
 
   // Returns current default socket. This is the socket over which all
   // QUIC packets are sent. This default socket can change, so do not store the
   // returned socket.
   const DatagramClientSocket* GetDefaultSocket() const;
 
   bool IsAuthorized(const std::string& hostname) override;
 
@@ skipping 86 matching lines @@
   int streams_pushed_count_;
   int streams_pushed_and_claimed_count_;
   // Stores packet that witnesses socket write error. This packet is
   // written to a new socket after migration completes.
   scoped_refptr<StringIOBuffer> packet_;
   // TODO(jri): Replace use of migration_pending_ sockets_.size().
   // When a task is posted for MigrateSessionOnError, pass in
   // sockets_.size(). Then in MigrateSessionOnError, check to see if
   // the current sockets_.size() == the passed in value.
   bool migration_pending_;  // True while migration is underway.
+  bool migration_alarm_pending_;  // True when migration alarm is armed.
   base::WeakPtrFactory<QuicChromiumClientSession> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicChromiumClientSession);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CHROMIUM_CLIENT_SESSION_H_